The errata for the book are given below. If you believe you've found an error, please send email to errors@buildinglinuxvpns.net and we'll check it out.

Note: After the book went to print, there were several vulnerabilities
found in the CIPE, VTun, and Tinc protocols. You can read
the list of vulnerabilities here.
Corrections to the problems are in the work, so check on the
websites for the individual software packages.

Page

Correction

48

CIDR typo

In the network with two hosts, the syntax should be
/30 instead of /252

79-80

Full path to pppd

In the sudo command, the third line reads

sudo pppd noauth ...

You may need to use the full pathname to pppd
which is usually /usr/sbin/pppd. This change
carries over to page 80 where this line's purpose is explained.

112

File listing typo

In the first ls listing (the one run on bears-server,)
the file client.pem should read client.cert.

114

/etc/sudoers typo

The snippet from /etc/sudoers has a typo. The
name should read sslvpn, not sshlvpn

156

Doubled numbers

In the list under "Creating a VPN with IPSec", items number three
and number four have the same index.

Thanks to Wai-hok Cheng

168-169

Misplaced labels on Figures 6.2 and 6.3

10.1.10.50 and 10.125.5.241 should be
drawn next to the eth0 (external) interfaces of the gateways.
@de.exemplify.com and @cn.exemplify.com
should be placed on top of the left and right gateways, respectively.

Thanks to Richard Bejtlich

180

Typo

In the sample ipsec.secrets file, the indices should read
ex1.exemplify.com and ex2.exemplify.com.

Thanks to Shashank Khanvilkar.

185

IP address typo

In the sample host-host configuration file, the IP address set as the
rightnexthop should read 10.125.5.1

Thanks to Giovanni Q.

211

Double untar

In the section "Installing pptp-linux", we have you untar and cd
twice. This was required for the version of pptp-linux at the time
the book was written. Newer versions do not have a tarball
within the tarball, so once is sufficient.

233

Options name typo

In the sample pppd options file, the name argument
should be pptp, not pptpd, in order
to match the chap-secrets syntax.

250

IP address typo

2nd paragraph: "From our network diagram, we see that the
tunnel interface on the server side will be configured as
192.168.192.254, on the network as 192.168.254.252."

Should read: "From our network diagram, we see that the
tunnel interface on the server side will be configured
as 192.168.254.254, on the client side as 192.168.254.253."